A heartwarming Passover picture book about the beloved Jewish holiday from award-winning author Leslie Kimmelman. A young boy and his family gather together to host a seder and celebrate the Festival of Freedom, filled with delicious dishes and an endless parade of guests. For Ethan and his family, Passover, the Festival of Freedom, is a holiday full of longstanding traditions, food, family, and great company. And at Ethan's family seder, one message of the Haggadah is never forgotten: let all who are hungry, come and eat. This year, however, Ethan is anticipating a very small seder. Until . Knock, Knock, Knock. Each unexpected guest brings something surprising and special, reminding us all that the seder's most essential ingredient is community.